package com.liang.gulimall.cart.interceptor;

import com.liang.common.constant.AuthServerConstant;
import com.liang.common.constant.CartConstant;
import com.liang.common.vo.MemberVo;
import com.liang.gulimall.cart.vo.UserInfoTo;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * 拦截器，在目标方法执行前执行，判断用户的登录状态
 *
 */
@Component
public class CartInterceptor implements HandlerInterceptor {
    /**
     * 同一个线程共享数据
     */
    public static ThreadLocal<UserInfoTo> toThreadLocal=new ThreadLocal<>();

    /**
     * 在目标方法执行前执行
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request,
                             HttpServletResponse response,
                             Object handler) throws Exception {
        UserInfoTo userInfoTo = new UserInfoTo();
        HttpSession session = request.getSession();
        MemberVo memberVo = (MemberVo) session.getAttribute(AuthServerConstant.LOGIN_USER);
        if (memberVo!=null){
            //已登录
            userInfoTo.setUserId(memberVo.getId());
        }
        Cookie[] cookies = request.getCookies();
        if (cookies!=null && cookies.length>0){
            for (Cookie cookie : cookies) {
                if (cookie.getName().equals(CartConstant.TEMP_USER_COOKIE_NAME)){
                    userInfoTo.setFlag(true);
                    userInfoTo.setUserKey(cookie.getValue());
                }
            }
        }
        //如果没有临时用户
        if (StringUtils.isEmpty(userInfoTo.getUserKey())){
            userInfoTo.setUserKey(UUID.randomUUID().toString());
        }

        toThreadLocal.set(userInfoTo);
        return true;
    }

    /**
     * 业务执行之后,浏览器保存临时用户
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        UserInfoTo userInfoTo = toThreadLocal.get();
        //浏览器保存临时用户
        if (!userInfoTo.isFlag()){//没有浏览器保存临时用户
            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
            cookie.setDomain("gulimall.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
            response.addCookie(cookie);
        }
    }
}
